feat: Implement Anthropic Claude LLM integration

.github/PULL_REQUEST_TEMPLATE.md

@@ -3,9 +3,9 @@
 
 ## Changes
 <!-- List specific changes made in this PR -->
-- 
-- 
-- 
+-
+-
+-
 
 ## Type of Change
 <!-- Check all that apply -->

README.md

@@ -144,7 +144,7 @@ autorca run \
 
 ```python
 from datetime import datetime
-from autorca_core import run_rca, DataSourcesConfig
+from autorca_core import run_rca, DataSourcesConfig, AnthropicLLM
 
 # Define the incident time window
 window = (
@@ -172,6 +172,35 @@ print(f"Confidence: {result.root_cause_candidates[0].confidence:.0%}")
 print(result.summary)
 ```
 
+### With LLM Enhancement (Anthropic Claude)
+
+```python
+import os
+from autorca_core import run_rca, DataSourcesConfig, AnthropicLLM
+
+# Initialize Anthropic LLM (requires ANTHROPIC_API_KEY env var)
+llm = AnthropicLLM(
+    api_key=os.getenv("ANTHROPIC_API_KEY"),
+    model="claude-3-5-sonnet-20241022",
+    max_tokens=2048,
+)
+
+# Run RCA with LLM enhancement
+result = run_rca(
+    incident_window=window,
+    primary_symptom="API 500 errors",
+    data_sources=sources,
+    llm=llm,  # Add LLM for enhanced summaries
+)
+
+# Get comprehensive AI-generated analysis
+print(result.summary)  # Structured RCA with executive summary, impact assessment, and remediation
+
+# Check token usage and costs
+stats = llm.get_usage_stats()
+print(f"Tokens used: {stats['total_tokens']}, Cost: ${stats['total_cost_usd']:.4f}")
+```
+
 ---
 
 ## How This Fits an Autonomous Ops Stack

autorca_core/__init__.py

@@ -12,6 +12,7 @@
 from autorca_core.model.events import Event, LogEvent, MetricPoint, Span
 from autorca_core.model.graph import Service, Dependency, IncidentNode
 from autorca_core.reasoning.loop import run_rca, RCARunResult
+from autorca_core.reasoning.llm import AnthropicLLM, DummyLLM
 from autorca_core.logging import configure_logging, get_logger
 from autorca_core.config import ThresholdConfig
 from autorca_core.validation import IngestionLimits, ValidationError
@@ -26,6 +27,8 @@
     "IncidentNode",
     "run_rca",
     "RCARunResult",
+    "AnthropicLLM",
+    "DummyLLM",
     "configure_logging",
     "get_logger",
     "ThresholdConfig",